The Methods of Enumeration in Microbes

••• gorodenkoff/iStock/GettyImages

The methods of enumeration in microbes can be divided into four categories. Direct methods involve counting the microbes, while indirect methods involve estimation. Viable methods only count cells that are metabolically active, while total counts include dead and inactive cells.

Direct/Viable

A direct/viable method involves a standard plate count, in which repeated dilutions of a sample are counted to calculate the count in the original sample.

Indirect/Viable

Indirect/viable methods such as MPN (most probable number) involve making a statistical inference about the microbe count based on patterns of growth.

Direct/Total

The microbes are counted with the aid of fluorescent stains and dyes, which make the microbes visible with the aid of a fluorescent microscope.

Indirect/Total

Spectroscopy is a form of indirect/total enumeration, which involves estimating the amount of microbes based on the amount of light passed through the culture by a spectrophotometer.

Related Articles

What Is Enumeration in Microbiology?
What Is a CFU in Microbiology?
How to Count Colonies in Microbiology
How to Calculate the Corrected WBC Count
Microbiology vs. Biochemistry
What is Turbidity & What Does It Indicate in Microbiology?
How to Calculate Variance From Standard Error
How to Make Oxalic Acid
The Advantages of Stained Bacteria
How to Count Cells with a Microscope
How to Test for Potassium Iodide
The Microorganisms Found in Sewage
How to Change 1/4 to a Decimal Form
Why Are Agar Plates Kept Inverted Whenever Possible?
How to Calculate Absorbance
How to Calculate Incidence & Prevalence
How to Calculate Success Rate
The Role of Microbes in Industry
How to Calculate Stanine Scores
How to Calculate Recombination Fraction

Dont Go!

We Have More Great Sciencing Articles!